Team:UT Dallas/project part3


How They Work: Quorum sensing molecules are naturally used by S. mutans to regulate population growth and competency. At normal levels, Competency Stimulating Peptide (CSP) allows a local population of S. mutans to share plasmids and grow. When the concentration of CSP gets high CSP activates a genetic pathway that causes some cells to activate cell-death. This allows the colony to remain at sustainable levels. We can take advantage of this natural population control to cause the equilibrium concentration of S. mutans in the oral cavity to decrease drastically. E. coli can produce CSP constitutively at a high rate. When placed in the mouth, these engineered E. coli will raise the concentration of CSP and cause the death of any nearby S. mutans cells. The natural quorum signaling system involves five gene products encoded by: ComA, ComB, ComC, ComD, ComE. The comC gene encodes a competence-stimulating peptide (CSP) precursor. ComC and ComDE lie adjacent on the chromosome and, together with their gene products, constitute a peptide (CSP)-signaling system including a generating pathway (comC) and a responding pathway (comDE).

What We Did: We attempted to isolate the genes from the S. mutans natural quorum signaling system.